#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>



int main()

{

    int num, count = 0;

    scanf("%d", &num);

    count += num;

    while (num)

    {

        count += num / 2;

        if ((num % 2 == 1)&&num>=2)
        {
            num = num / 2 + 1;
        }
        else
            num = num / 2;
        

    }

    printf("%d", count);

    return 0;

}